Recommendation 4.3.8:
Use a large font and let the user adjust the size
Benefits Users
Visual
Relevant W3C Guidance
Phase 1: Gather & Organize
[none]
Phase 2: Design & Implement
Design Question
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How big is too big for your chatbot’s font size?
- Bigger is usually better. This applies to all forms of text, including button labels, images of text, and the size of icons. However, text may be too large if it causes messages to be too long to read without scrolling.
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Will you dedicate the resources toward native zoom and magnification, or will you focus that effort toward testing with third-party tools?
- Most web browsers and computers allow the user to resize the content font. However, you will not have complete control over how the UI looks when enlarged. Offering a capability to zoom or enlarge the text within the chatbot will give you greater control over the appearance of the chatbot.
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How will you let users adjust the font size?
- Offer a customizable font size to serve the widest range of users. Sliders or numerical inputs let users choose from a range of sizes, whereas a finite set of sizes (e.g., 100%, 150%, 200%) serves a wide range of users while allowing the designer to control the look of the chatbot.
Tip
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Number or bullet next steps so that they are concise and easy to interpret. Prioritize the steps in order of importance, most important being first.
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Support font size up to 200% of the standard font size.
Phase 3: Test & Evaluate
Self Check
- Can the user resize the chatbot text?
Ask the User
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Is the default font size easy to read?
- This question is subjective; use a Likert scale. This question should be asked post-study.
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Are you easily able to adjust the font size to something convenient for you?
- This question is subjective; use a Likert scale. This question should be asked post-study.
Testing
- Check the visual appearance of the chatbot with multiple font sizes, both from native font size controls within the chatbot (if present) and with browser or device enlargement capabilities.